Activation energy and chemical reaction impact on three-dimensional micropolar Casson nanofluid flow under Lorentz force phenomenon

Efficient thermal management is essential in modern engineering systems, particularly where temperature-sensitive processes are involved. This study focuses on understanding the role of Arrhenius activation energy in the behavior of a three-dimensional, incompressible, and electrically conducting Casson nanofluid flowing over a porous stretching surface. The importance of this work lies in its potential to improve predictive modeling in applications such as chemical processing, material manufacturing, and energy systems. The analysis incorporates thermal radiation, internal heat generation, and magnetic effects, which are relevant to real-world industrial environments. By transforming the governing partial differential equations into a set of ordinary differential equations using similarity variables, numerical solutions were obtained through MATLAB three-stage Lobatto IIIA solver. Key findings indicate that increasing the magnetic parameter from 0.5 to 0.7 results in a 6% increase in the heat transfer rate, a 2% decrease in skin friction, and a 12% decrease in the mass transfer rate. The study also reveals that higher Eckert numbers elevate both velocity and temperature profiles while lowering the heat transfer rate and shear stress. These results highlight the complex interplay between electromagnetic and thermal effects in nanofluid flows. The novelty of this work lies in its comprehensive integration of activation energy, non-Newtonian fluid behavior, and multiple thermal effects within a three-dimensional framework, advancing existing models and offering practical insights for optimizing energy and heat transfer systems.